GlaxoSmithKline (GSK) has jolted the pharmaceutical community with its abrupt decision to sever ties with Sosei Heptares, a move that comes just as the collaboration was poised to advance an inflammatory bowel disease asset into clinical trials. This unforeseen development, reportedly tied to internal shifts within GSK’s immunology unit, involves the complete relinquishment of rights to the program, bringing an untimely end to a partnership established three years ago.
The initial agreement, valued at a substantial £34 million ($43 million), granted GSK global rights to a diverse portfolio of GPR35 agonists, positioning the pharmaceutical giant at the forefront of innovative drug development targeting G protein-coupled receptors in the intricate landscape of the gastrointestinal tract.
Throughout the collaboration, GSK steadily contributed through incremental payments linked to achieved milestones, facilitating the accumulation of critical mechanistic, preclinical, and safety data. Notably, these efforts culminated in the approval to commence human trials in the UK for the promising candidate, GSK4381406. However, in an unexpected turn, GSK has chosen to discontinue the program, citing a strategic realignment marked by the “deprioritization and discontinuation” of its development trajectory.
This strategic shift is attributed to significant alterations within GSK’s immunology research leadership and overall research strategy. Crucially, Sosei clarified that this strategic pivot was not motivated by any scientific, preclinical, or safety concerns related to GSK4381406.
The restructuring of GSK’s immunology team, disclosed in September, unfolded with the departure of Dr. John Lepore, the Senior Vice President and Head of Research, a key figure in the Sosei collaboration. Concurrently, GSK initiated a comprehensive reorganization of its research efforts, segmenting them into three teams more closely aligned with its core therapeutic groups: respiratory and immunology; vaccines and infectious diseases; and oncology.
Sosei has showcased resilience in response to GSK’s unexpected withdrawal, confirming its commitment to autonomously navigate the authorized phase 1 trial of GSK4381406. This independent trajectory is complemented by ongoing evaluations of potential pathways for advancing the program, including internal development or establishing a new collaboration. At the heart of Sosei’s strategic framework is the model of advancing candidates into early clinical development and subsequently seeking collaborative partnerships, exemplified by its recent acquisition of Idorsia’s operations in Japan and the Asia-Pacific region (excluding China) for a substantial sum of 400 million Swiss francs ($454 million).
Maintaining an optimistic outlook, Sosei references an independent commercial analysis emphasizing a global peak sales potential exceeding $3 billion for GSK4381406, attributed to its unique target product profile. Central to the promise of this molecule is its targeting of GPR35, a receptor that has increasingly captivated researchers as barriers to its study, such as differences between human and rodent biology, have been overcome, revealing its association with a spectrum of diseases.